Devices and methods for performing in-vivo imaging of passages or cavities within a body are known in the art. Such devices may include, inter alia, various endoscopic imaging systems and devices for performing imaging in various internal body cavities.
Reference is now made to FIG. 1 which is a schematic diagram illustrating an embodiment of an autonomous in-vivo imaging device. The device 10A typically includes a capsule-like housing 18 having a wall 18A. The device 10A has an optical window 21 and an imaging system for obtaining images from inside a body cavity or lumen, such as the GI tract. The imaging system may include an illumination unit 23. The illumination unit 23 may include one or more light sources 23A. The one or more right sources 23A may be a white light emitting diode (LED), or any other suitable light source, known in the art, The imaging system of the device 10A may include an imager 24, such as a CMOS or CCD, which acquires the images and an optical system 22 which focuses the images onto the imager 24. Typically, the imager 24 is arranged so that it's surface 27 is perpendicular to the longitudinal axis 19 of the device 10A. The illumination unit 23 illuminates the inner portions of the body lumen through an optical window 21. Device 10A further includes a transmitter 26 and an antenna 27 for transmitting the image signal of the imager 24, and one or more power sources 25. The power source(s) 26 may be any suitable power sources such as but not limited to silver oxide batteries, lithium batteries, or other electrochemical cells having a high energy density, or the like. The power source(s) 25 may provide power to the electrical elements of the device 10A.
Typically, in the gastrointestinal application, as the device 10A is transported through the gastrointestinal (GI) tract, the imager, such as but not limited to a multi-pixel CMOS imager acquires images (frames) which are processed and transmitted to an external receiver/recorder (not shown) worn by the patient for recording and storage. The recorded data may then be downloaded from the receiver/recorder to a computer or workstation (not shown) for display and analysis. During the movement of the device 10A through the GI tract, the imager may acquire frames at a fixed or at a variable frame acquisition rate. For example, in one embodiment the imager (such as, but not limited to a CMOS imager) may acquire images at a fixed rate of two frames per second (2 Hz). However, other different frame rates may also be used, depending, inter alia, on the type and characteristics of the specific imager or camera or sensor array implementation which is used, and on the available transmission bandwidth of the transmitter 26. The downloaded images may be displayed by the workstation by replaying them at a desired frame rate. This way, the expert or physician examining the data is provided with a movie-like video playback which may enable the physician to review the passage of the device through the GI tact.
It may generally be desirable to decrease the size and particularly the cross sectional area of in vivo imaging devices, such as the device 10A of FIG. 1, or of imaging devices that are to be inserted into working channels of endoscope-like devices, or integrated into catheter-like devices which may be used in conjunction with guide wires, or the like. Smaller catheter like devices with reduced area may be inserted into narrower body cavities or lumens, such as for example, the coronary arteries, the urethra, the common bile duct, or the like and may also be easier to insert into working channels of other devices such as endoscopes, laparoscopes, gastroscopes, or the like.
Decreasing the cross-sectional area of such devices may be limited by the cross-sectional area of the imaging sensor, such as for example the imager 24 of FIG. 1